Steam-engine



N0. 6|2,952. Patented Oct. 25, I898. G. MARSHALL.

STEAM ENGINE.

(Application file'd Apr. 27. 1898.! Model.) 7 2 Sheets-Sheet 1.

No. 6I2,952. Patented Oct. 25, I898.

G. MARSHALL.

STEAM ENGINE.

(Application filed Apr. 27, 1898.) (N0 Modem 2 Sheets-Sheet 2..

gwve/wfm #30736 MSW) UNITED STATES PATENT OFFICE.

GEORGE MARSHALL, OF FREMONT, NEBRASKA.

STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent No. 612,952, dated October 25, 1898.

Application filed April 27, 1898. Serial No. 679,033. (No model.)

To all whom it may concern.-

Be it known that I, GEORGE MARSHALL, a citizen of the United States, residing at Fremont, in the county of Dodge and State of Nebraska,have invented certain new and useful Improvements in Steam-Engines, of which the following is a specification.

My invention relates to that class of engines which are illustrated in my Patents No. 504,399, of September 5, 1893, and No. 549,520, of November 12, 1895.

The object of my present invention is to so improve'the mechanism shown in my patents above mentioned that the admission and eX- haust valves may be more quickly and accurately operated.

In the accompanying drawings, illustrating my invention, Figure l'shows a side elevation of a steam-engine with my improvements applied. Fig. 2 is a plan view thereof.

The eccentric A is mounted on the main shaft B, and the eccentric-strap O encircles the eccentric in the usual manner. The slotted link D is precisely the same in form as that shown in my prior patents, and it is connected at its lower end with a forked lever E, which is pivoted to the pivot-block F or to brackets on the bed-plate. The governor G is of the same construction as that shown in my before-mentioned patents, and it is connected by a rod H with a radius-bar I. In my prior patents the bar H is a straight bar. By my present improvements I bend or curve the lower end of the bar, h, as by this arrangement the end of the radius-bar which is adj ustable in the slot of the slotted link is more readily moved. The radius-bar I is pivotally connected at t with an upright lever K, which is pivotally connected at with a supportingbracket L. The opposite end of the radiusbar I carries a block .I, which is adapted to move up and down in the slotted link. The connection between the radius-bar I and the upright lever K is below the upper end of the lever. At the upper end of the lever is pivotally connected a rod M, the opposite end of which is connected at m with a wrist-plate N. The wrist-plate is pivoted midway between its endsat n to the steam-cylinder, the lower end of the plate being sector-shaped and pivotally connected with two links 0, which in turn are pivotally connected to upright levers P P. These levers are pivotally connected at their lower ends 19 to brackets Q, mounted on the bed-plate. At their upper ends the levers are connected by means of links R with arms 1, projecting from the rotary admission-valves.

It will be observed that the pivot of the wrist-plate is arranged between the pivots of the rod M and the links 0, and the levers, links, and arms are so arranged that the admission-valves are operated at the proper time to admit steam and to cut it'ofih The arrangement of lovers is such as to make the admission-valves quick-acting, and the arrangement is also such as to require but little power to operate them. The exhaust-valves S are provided with arms s,connected together by a link T and also by a rod U with an upright lever V, pivoted at o to one of the standards, and connected at its upper end to a rod W, pivotally connected to the upper end of the slotted link B.

It will be observed that the general organization of the apparatus shown' in the drawings is quite similar to that shown in my before-mentioned patents, the main diiferences being in the use of the forked lever E in place of the trunnions shown in my prior patents, the curved rod or link H, and the arrangement involving the use of a wrist-plate in connection with the upright levers or arms P P, which are connected to the admissionvalves.

I claim as my invention- The combination of the main shaft, the eccentric thereon, the slotted link, the upright lever, K, the radius-bar connecting the upright lever with the slotted link, the wristplate, an operating-rod connecting the lever, K, with the wrist-plate, the upright levers or arms pivotally connected at their lower ends to the frame of the machine, links connecting said upright levers with the wrist-plate and a pivot for the wrist-plate interposed between the connections between the links and the connection between the wrist-plate and its operating-rod.

In testimony whereof I have hereunto subscribed my name.

GEORGE MARSHALL.

Witnesses:

W. H. FOWLER,

L. D. RICHARDS. 

